The present invention is directed toward wound compression dressings for control of bleeding from wounds.
Bleeding control is a major consideration in the emergency treatment of acute trauma. Rapid and effective application of compression at the scene of a traumatic incident until arrival at a medical facility has been found to significantly decrease loss of blood from wounds. As result, chances for survival of trauma victims and/or chances for avoiding a loss of their limbs are improved when compression is so applied. Traditional methods of bleeding control include those using direct compression over a wound surface, usually employing an absorbent layer, and indirect compression through application of a tourniquet, the tourniquet being tightly applied proximal to the wound.
With indirect compression, use of a tourniquet typically entails bounding an elastic material tightly around a wounded body part proximal to a wound. The tourniquet is sometimes applied with sufficient constricting force to cause ischemia distally to the site of application. While this highly effective and widely used method of bleeding control is advantageous in that it does not require an individual to apply the pressure, ischemia that can be induced thereby can be both extremely painful to the victim and even the cause of soft tissue and neurological damage to distal body parts.
Direct compression is often effective in controlling bleeding; however, direct compression is often impractical in many emergency situations due to the need for one to continually apply such pressure, often denying that individual the ability to effectively perform other tasks. Further, heavy direct compression may aggravate damage to wounded tissues and fractures and is particularly inconvenient to apply over irregularly shaped or sensitive body parts.
Alternatively, a variety of compression dressings are known for direct compression applications, many of which advantageously do not require that an individual actively administer the pressure. For example, elastic fabric wraps (e.g., those sold by 3M Co. under the COBAN and ACE trade designations) are often used as an outer layer in wound compression dressings in order to hold the inner layers in place and to apply compression to the wound. However, many elastic fabric wraps are non-adhesive and/or have inadequate recovery after being stretched around a wound, which causes them to shift with motion, compromising their comfort and compression capabilities. Therefore, such elastic fabric wraps often need to be fastened or bonded to an adhesive, which is also not ideal in that many conventionally used adhesives lose their tack when exposed to moist environments (e.g., exudates from a wound), which often leads to shifting of the dressing after its application over a wound.
Foam compression dressings available from Smith & Nephew under the ALLEVYN trade designation are described as containing a highly absorbent material embedded in a self-adherent polyurethane matrix. The dressing is covered with a waterproof polyurethane film, which film is both permeable to oxygen and water vapor as well as being bacteria-proof. The dressings are described as employing all the proven benefits of a moist wound environment without any breakdown of the dressing caused by contact with exudate. Further, the dressings are described as being slightly adherent in that they adhere well to dry, intact skin, but will not adhere to a wound's surface. The slight adherence to dry skin is stated to hold the dressing in place during application of the compression bandage. The dressings are sold in packages having multiple dressing pieces, with each piece having dimensions of 6 inches (15 cm) by 8 inches (20 cm) or in packages with multiple smaller, approximately square-shaped pieces.
U.S. Pat. No. 5,939,339 discloses a wound compression dressing described as being a porous, self-adhering, elastic bandage; an absorbent layer covering at least a portion of the self-adhering substrate; and means adapted to flexibly bond the self-adhering substrate to the absorbent layer. The bandage may be compressively wrapped around a wound and is stated to be capable of absorbing fluids and wound exudate. A preferred embodiment of the wound compression dressing therein is described as one that does not adhere to clothing, hair, or skin and that has a compressive force when extended that provides a therapeutic benefit. An elastic substrate therein is described as comprising materials that are elastic, conformable, porous, self-adhering, and that provide adequate compression. It is stated that a material made of melt blown microfiber webs may also be used as the elastic substrate. Exemplary melt blown microfiber webs are described as being a variety of well-known thermoplastic elastomers, including polyurethane, styrene-isoprene block copolymer, styrene-butadiene block copolymer, and blends of these elastomers with polyolefins such as polypropylene and polyethylene. In addition, it is stated that the melt blown microfiber webs may include, but are not limited to, staple fibers, such as rayon, polyester, nylon, cotton, LANSEAL absorbent fiber (Japan Exlan Co., Ltd.; Osaka, Japan), cellulose, or polypropylene fibers, to provide a blend of elastomeric and staple fibers. Suitable melt blown microfiber webs are described as having elongations of 30%-500% with an elastic recovery of about 90%. In order to increase the self-adherence of the dressings therein, coating both sides of the elastic substrate with a natural rubber latex or adhesive having low tack is described.
U.S. Pat. No. 6,573,419 describes an elastic adhesive wound compression dressing for control of bleeding and for dressing bleeding wounds. The wound compression dressing comprises a self-adhering, elastic bandage strip designed for, when wrapped around a body part, exerting a compressive force of between about 1 to about 180 mm Hg that is sufficient to hold the wound compression dressing in place for a period of time in order to provide a therapeutic effect to a wound. The dressing comprises an absorbent pad affixed to an inner side of a terminal portion or to a terminal end of the self-adhering, elastic bandage strip.
In a preferred embodiment described therein, the dressing comprises non-woven elastomeric fibers and/or clear polyolefin polymer or copolymer films having firm elastic extendibility in longitudinal and vertical directions and an adhesive, with the dressing having self-adhesive properties sufficient to cause two adjacent layers of the bandage to remain adhered to one another without use of a fastening mechanism. Similar to U.S. Pat. No. 5,939,339, it is stated that a material made of melt blown microfiber webs may also be used in the strip of the invention. Exemplary melt blown microfiber webs are described as being a variety of well-known thermoplastic elastomers, including polyurethane, styrene-isoprene block copolymer, styrene-butadiene block copolymer, and blends of these elastomers with polyolefins such as polypropylene and polyethylene. In addition, it is stated that the melt blown microfiber webs may include, but are not limited to, staple fibers, such as rayon, polyester, nylon, cotton, LANSEAL absorbent fiber (Japan Exlan Co., Ltd.; Osaka, Japan), cellulose, or polypropylene fibers, to provide a blend of elastomeric and staple fibers.
In another preferred embodiment of the invention described therein, the self-adhering elastic strip is constructed of a transparent material. In this manner, the dressing allows for monitoring of continued bleeding even when applied. Preferred materials are described as clear or printed polyolefin or copolymer films having both firm extendibility in the longitudinal and vertical directions and self-adhesive properties. Exemplary films include a polyethylene film consisting of 54% low-density polyethylene, 40% copolymer of ethylene and octene-1, and 6% SEBS-copolymer. This film is described as having a thickness of 100 microns, modulus at 25% elongation of 0.6 (M.D.) and 0.5 (C.D.) Kg/mm2, tensile strength of 2.0 (M.D.) and 2.8 (C.D.) Kg/mm2, elongation at break of 600% (M.D.) and 1,000% (C.D.), adhesion strength of 1,600 g/10 cm and adhesion to steel of 16.4 Newtons/inch. Another exemplary film described therein is that sold by the Dow Chemical Co. under the AFFINITY KC 8852 trade designation.
A need exists for alternative wound compression dressings and associated methods, particularly for use in providing direct compression over a wound. While many wound compression dressings are known, alternative dressings are desirable, factoring in certain considerations that become even more important depending on the incident scene. When the scene of a traumatic incident is a battlefield, for example, an important consideration is size and weight of the wound compression dressing that must often be transported along with other essential provisions on a combat soldier. Further, due to the inherently unstable conditions on a battlefield, ease of application and avoidance of detection by the enemy while applying the compression are important considerations. As with other applications, continued adherence of wound compression dressings over a wound and adequate compression until bleeding of the wound halts or the wounded arrives at a medical facility also continues to be an important consideration when the wound compression dressing is used on a battlefield or similar remote location.